1. Field of the Invention
The present invention relates to an instrument and method for accurately aligning cuts in a femur bone during Total Knee Replacement (TKR) surgery, and in particular to a trochlear clamp that allows positioning of the femoral component relative to the trochlear groove.
2. Description of Related Art
A total knee replacement or prosthesis, substitutes for a patient's arthritic or otherwise dysfunctional natural knee joint. The prosthesis offers the patient an alternative treatment for the chronic pain and discomfort often associated with such problems.
Burstein et al. U.S. Pat. No. 4,298,992 illustrates a widely used total knee joint prosthesis known as the Insall-Burstein (I/B) knee. Such prostheses comprise a femoral component which is attached to the patient's femur, a tibial component attached to the patient's tibia, and a patellar component attached to the patient's patella. To use this prosthesis, it is necessary to shape by resection the patient's femur, tibia and patella. The tibia and patella are shaped by a flat cut. In the case of the I/B prosthesis, the femoral component requires five cuts in the distal end of the femur. These cuts conform to complementary portions of the femoral component which engage the bone. It is important that these femoral cuts be precisely located to insure the patient's natural anatomic limb alignment and normal anatomical movement.
It is therefore desirable to develop an instrument for properly positioning a cutting guide to ensure the accuracy in the location of the five cuts in the femur bone.